A camera for taking a picture, which includes a so-called zoom lens capable of varying a photographing magnification according to need, is widely distributed. With this zoom lens, the photographing magnification can be varied between a telephoto state capable of photographing a distance at a magnification and a wide-angle state capable of photographing a wide area by means of operation switches provided in the camera. In order to vary the photographing magnification as described above, a plurality of lens groups each having at least one lens is combined, and each of the lens groups is driven in the optical axis direction of the lens groups. A camera for taking a picture, which includes a so-called zoom lens capable of varying a photographing magnification according to need, is widely distrusted. With this zoom lens, the photographing magnification can be varied between a telephoto state capable of photographing a distance at a magnification and a wide-angle state capable of photographing a wide area by means of operation switches provided in the camera. In order to vary the photographing magnification as described above, a plurality of lens groups each having at least one lens is combined, and each of the lens groups is driven in the optical axis direction of the lens groups.
When driving the above lens groups, a method of driving a mechanical mechanism, which can change a position of each of the lens groups in conjunction with each other, by means of hand or a motor is generally used (for example, reference to H06-160699A).